Jan Breet Posted September 4, 2015 Share Posted September 4, 2015 I have an project coming up for farmers nearby Mafeking. The all have 3 phase motors on their bore holes. My question is, is it cheaper to change the motor to single phase, or must I get a 3 phase inverter solar system? Quote Link to comment Share on other sites More sharing options...
Guest Posted September 4, 2015 Share Posted September 4, 2015 Just a question from another angle. Depending on the use, is it not and option to invest in solar pumps with solar panels? Quote Link to comment Share on other sites More sharing options...
Gnome Posted September 4, 2015 Share Posted September 4, 2015 There are various reasons why getting a solar pump would be better. Power factor, current requirements. Three phase may well be more efficient which is important for solar. But it will cost a lot more inverter wise. But a bad power factor will be really, really wasteful in which case an actual solar pump would be far better choice. Power factor in 3 phase motors can easily be a problem, hence mentioning it. Quote Link to comment Share on other sites More sharing options...
Chris Hobson Posted September 4, 2015 Share Posted September 4, 2015 There is a limit on the size of single phase motors. About a 5kW is the biggest I know of. If they are pumping large volumes of water then that necessitates a solar pump or remaining on 3 phase. Quote Link to comment Share on other sites More sharing options...
Eugene Posted September 4, 2015 Share Posted September 4, 2015 Also depends on whether it's submersible or above ground pumps. Quote Link to comment Share on other sites More sharing options...
Jan Breet Posted September 5, 2015 Author Share Posted September 5, 2015 Where can I get the best price on Submersible Solar pumps please? Quote Link to comment Share on other sites More sharing options...
Guest Posted September 5, 2015 Share Posted September 5, 2015 Here is one place: http://www.solarsolved.co.za/index.php/products/submersible-pumps Quote Link to comment Share on other sites More sharing options...
Chris Hobson Posted September 5, 2015 Share Posted September 5, 2015 www.allpower.co.za submersible pumps are manufactured in SA. I have one and I am happy with it. They not as good as a Grundfos or Lorenz but Quote Link to comment Share on other sites More sharing options...
SilverNodashi Posted September 6, 2015 Share Posted September 6, 2015 I'm sitting in the same boat. Need to solarize 3 pumps on the farm. One of them is an "ancient" pump that uses about 4.5A on 400V. It's a belt driven pump and the electrical motor is probably 10 years old. The one quote I got for a 2.2Kw solar system was R72,000! Quote Link to comment Share on other sites More sharing options...
Jan Breet Posted September 7, 2015 Author Share Posted September 7, 2015 What backup can I use for a submersible pump. If the sun is not shinning for more than 7 days? Quote Link to comment Share on other sites More sharing options...
Chris Hobson Posted September 7, 2015 Share Posted September 7, 2015 I think that 7 days without sun would be so infrequent event that a generator would be the cheapest option if grid is not going to be available. Quote Link to comment Share on other sites More sharing options...
Eugene Posted September 7, 2015 Share Posted September 7, 2015 What backup can I use for a submersible pump. If the sun is not shinning for more than 7 days? Probably rain quite a bit during 7 days without sun. Any above ground tanks to pump into during sunny times ?. Quote Link to comment Share on other sites More sharing options...
SilverNodashi Posted September 7, 2015 Share Posted September 7, 2015 What backup can I use for a submersible pump. If the sun is not shinning for more than 7 days? Batteries, but as Chris said it would be more economical to have a genset if the sun doesn't shine for 7 days!. Quote Link to comment Share on other sites More sharing options...
Jan Breet Posted September 7, 2015 Author Share Posted September 7, 2015 Thanks very much for feedback!!! Quote Link to comment Share on other sites More sharing options...
Guest Posted September 7, 2015 Share Posted September 7, 2015 If there is already 2phase power at the pump The all have 3 phase motors on their bore holes. If there is 3 phase already at the pump, why not use that in case of emergency? Quote Link to comment Share on other sites More sharing options...
Chris Hobson Posted September 7, 2015 Share Posted September 7, 2015 Rural Eskom users pay through the nose - sometimes R2500 -R3000 in line fees, levies etc. BEFORE you have used a SINGLE unit of power. If you are going solar under these circumstances you do not want to maintain your Eskom connection for the "what-if" scenarios. You plow that R2500 into your installation and make other alternatives for rainy days. Quote Link to comment Share on other sites More sharing options...
Jacques1s Posted April 20, 2017 Share Posted April 20, 2017 I have the same problem and looking into Three-Phase VSD Solar Pump Controller MicroCare has one. You do need a VSD compatable drive. The other option I found was at www.fullcirclesolar.co.za -- They have one that runs on all moters. Down side is that they all need around 500V ( Lots of panels ) Still worth it as the Eskom pump point alone coasts me R1800 a month. Quote Link to comment Share on other sites More sharing options...
jacobez Posted May 2, 2017 Share Posted May 2, 2017 An option would be to replace the 3P DOL starters with a 1P input - 3P ouput VSD. pilotfish 1 Quote Link to comment Share on other sites More sharing options...
SilverNodashi Posted May 16, 2017 Share Posted May 16, 2017 On 5/2/2017 at 0:00 PM, jacobez said: An option would be to replace the 3P DOL starters with a 1P input - 3P ouput VSD. We ended up installed 3x 5KVA Axpert inverters + solar panels, which then could be used for other purposes as well. Other brands could also be used but this was the cheapest option. Quote Link to comment Share on other sites More sharing options...
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